From 05f7ea7f6ef611a077fcbb983fb8d6a99e91e1f6 Mon Sep 17 00:00:00 2001 From: Andrea Merello Date: Tue, 20 Nov 2018 16:31:49 +0100 Subject: [PATCH] dmaengine: xilinx_dma: autodetect whether the HW supports scatter-gather The AXIDMA and CDMA HW can be either direct-access or scatter-gather version. These are SW incompatible. The driver can handle both versions: a DT property was used to tell the driver whether to assume the HW is in scatter-gather mode. This patch makes the driver to autodetect this information. The DT property is not required anymore. No changes for VDMA. Cc: Rob Herring Cc: Mark Rutland Cc: devicetree@vger.kernel.org Cc: Radhey Shyam Pandey Signed-off-by: Andrea Merello Reviewed-by: Radhey Shyam Pandey Signed-off-by: Vinod Koul --- drivers/dma/xilinx/xilinx_dma.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c index d59af2b33a99..b559efe06adb 100644 --- a/drivers/dma/xilinx/xilinx_dma.c +++ b/drivers/dma/xilinx/xilinx_dma.c @@ -86,6 +86,7 @@ #define XILINX_DMA_DMASR_DMA_DEC_ERR BIT(6) #define XILINX_DMA_DMASR_DMA_SLAVE_ERR BIT(5) #define XILINX_DMA_DMASR_DMA_INT_ERR BIT(4) +#define XILINX_DMA_DMASR_SG_MASK BIT(3) #define XILINX_DMA_DMASR_IDLE BIT(1) #define XILINX_DMA_DMASR_HALTED BIT(0) #define XILINX_DMA_DMASR_DELAY_MASK GENMASK(31, 24) @@ -414,7 +415,6 @@ struct xilinx_dma_config { * @dev: Device Structure * @common: DMA device structure * @chan: Driver specific DMA channel - * @has_sg: Specifies whether Scatter-Gather is present or not * @mcdma: Specifies whether Multi-Channel is present or not * @flush_on_fsync: Flush on frame sync * @ext_addr: Indicates 64 bit addressing is supported by dma device @@ -434,7 +434,6 @@ struct xilinx_dma_device { struct device *dev; struct dma_device common; struct xilinx_dma_chan *chan[XILINX_DMA_MAX_CHANS_PER_DEVICE]; - bool has_sg; bool mcdma; u32 flush_on_fsync; bool ext_addr; @@ -2421,7 +2420,6 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev, chan->dev = xdev->dev; chan->xdev = xdev; - chan->has_sg = xdev->has_sg; chan->desc_pendingcount = 0x0; chan->ext_addr = xdev->ext_addr; /* This variable ensures that descriptors are not @@ -2521,6 +2519,15 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev, chan->stop_transfer = xilinx_dma_stop_transfer; } + /* check if SG is enabled (only for AXIDMA and CDMA) */ + if (xdev->dma_config->dmatype != XDMA_TYPE_VDMA) { + if (dma_ctrl_read(chan, XILINX_DMA_REG_DMASR) & + XILINX_DMA_DMASR_SG_MASK) + chan->has_sg = true; + dev_dbg(chan->dev, "ch %d: SG %s\n", chan->id, + chan->has_sg ? "enabled" : "disabled"); + } + /* Initialize the tasklet */ tasklet_init(&chan->tasklet, xilinx_dma_do_tasklet, (unsigned long)chan); @@ -2659,7 +2666,6 @@ static int xilinx_dma_probe(struct platform_device *pdev) return PTR_ERR(xdev->regs); /* Retrieve the DMA engine properties from the device tree */ - xdev->has_sg = of_property_read_bool(node, "xlnx,include-sg"); xdev->max_buffer_len = GENMASK(XILINX_DMA_MAX_TRANS_LEN_MAX - 1, 0); if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) { -- 2.11.0